Horizontal reaction chamber comprised of nested, concentric tubes for use in water purification

ABSTRACT

The present invention includes a horizontal foam fractionation protein skimmer for removing organic waste material (dissolved organic compounds) from organic loaded water. The protein skimmer includes a horizontal reaction chamber connected to a foam collection chamber in which protein-loaded foam containing organic waste material is collected. The reaction chamber is comprised of a series of horizontally-directed, nested, concentric tubes for increasing the number and decreasing the size of bubbles to facilitate efficient removal of dissolved organic compounds. Each horizontal tube has either one or several small openings that are offset from the openings on the adjacent tube at a small angle, typically 10°. The openings are formed by either a single slit that runs along the length of each tube, or by a series of holes that runs along the length of each tube. Organic-loaded water is pumped through tubing into the reaction chamber. As water moves through the tubing, gas (e.g., air) is drawn in by eductors, creating a gas/water mixture. The gas/water mixture is distributed into the horizontal reaction chamber through a lateral manifold that tangentially injects the gas/water mixture at approximately equidistant points along the length of the reaction chamber. The gas/water mixture enters the largest of the nested horizontal tubes and is forced through the small opening(s) into the next smaller diameter tube. 
     Water travels circumferentially through adjacent tubes in a counter-current movement. The most central concentric tube carries the water out of the reaction chamber into the foam collection chamber. The water left behind is considerably more pure and free of contaminates and exits through tubing in the bottom of the foam collection chamber. The horizontal protein skimmer of the present invention is sectioned into individual components that facilitate transport and on-site assembly.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a Divisional of U.S. Ser. No. 10/692,510,filed Oct. 24, 2003 U.S. Pat. No. 6,849,189, which claims priority fromProvisional Application Ser. No. 60/422,161, filed Oct. 28, 2002,entitled “Horizontal Reaction Chamber Comprised of Nested, ConcentricTubes for Use in Water Purification” The disclosure of the abovereferences are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a horizontal foam fractionation proteinskimmer comprised of a horizontal reaction chamber for removing organicwaste material from organic loaded water such as in aquaria, lagoons,wastewater, or other organic-loaded water sources, to methods of makingsuch a horizontal protein skimmer, and to water purification methodsutilizing such a horizontal protein skimmer.

2. Introduction to the Invention

Improved means of purifying water from a variety of organic loaded watersources are necessary. Methods of water purification and maintenance ofgood water quality are essential in purifying water from aquaria,lagoons, and from any organic-loaded water source, such as in wastewatertreatment applications. This invention could also be useful for thepretreatment of effluent from agricultural wastewater applications suchas in pig or chicken farms. The present invention is in the field offoam fractionation protein skimmers which are used to remove organicwaste material from any organic loaded water source. For example,maintenance of water quality in aquarium tanks is a continuous andsubstantial challenge, particularly in public aquaria that have manylarge volume tanks. Organic waste contamination of water is a common andrecurrent problem in aquaria. Foam fractionation protein skimmers helppurify this contaminated water by using a naturally occurring foamfractionation action to produce a protein-loaded foam which contains theorganic waste material extracted from organic loaded water. Proteinskimmers are known and have been proven to be effective in helpingmaintain water quality in aquarium tanks.

A properly functioning protein skimmer effectively oxygenates water thatpasses through the body of the skimmer by introducing a large number ofsmall gas or air bubbles into the water. A protein skimmer also servesas a method for water purification by allowing introduced bubbles toreact with surrounding water molecules and pollutants to attach tosurfaces of bubbles. The bubble-water mixture becomes foam which can bereadily separated from the considerably more pure water that is producedby the protein skimmer. The bubbles are directed out of the reactionchamber of the skimmer and collected, along with adherent pollutants, ina collection vessel. In this manner, organic waste material can bepermanently removed from a water system.

Several features can make some protein skimmers more effective thanothers. Overall water flow rate through the protein skimmer isimportant. The more water that is processed per unit time generallymeans more waste material is removed and more gas exchange occurs. Theamount of contact time between air bubbles and water and the quality ofthis contact time is important as well. If bubbles are immediatelywithdrawn from the skimmer as soon as they are introduced, they may notbe fully saturated with waste material. If bubbles react with water in alaminar, non-turbulent fashion, contact time between bubbles and wastematerial is reduced and bubbles may not be fully saturated with wastematerial. In either case, maximum efficiency can be compromised.

The number and size of bubbles is also important. A large number ofbubbles increases the amount of waste material that can be skimmed outusing a protein skimmer. Numerous small bubbles afford greater surfacearea for the air-water interaction than do the same volume of largebubbles. These are important aspects of protein skimming whichcontribute to a given protein skimmer's efficiency and success. Ingeneral, the goal is to maximize the number and to minimize the size ofthe bubbles, and to maximize the length of time the bubbles are incontact with water.

Typical protein skimmers in public aquaria are very tall (e.g., greaterthan 8 feet in height), very bulky, and difficult to maintain. Limitedspace, both floor space and headspace, is often a major concern inpublic aquaria, particularly in aquaria in which displays are frequentlyadded, changed, or remodeled. These frequent alterations result intypical protein skimmers being too tall and too bulky to fit in many ofthe areas where they are needed. Additionally, most typical proteinskimmers require substantial maintenance, which is difficult and oftentreacherous on very tall protein skimmers, particularly as structuresare built around existing protein skimmers and space becomesincreasingly more limited.

The primary applications of the current invention have been conductedusing salt or brackish water (15 ppt–38 ppt), but the invention willlikely function in freshwater.

BRIEF SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a new foamfractionation protein skimmer for effectively removing organic wastematerial from any organic loaded water source. The skimmer operatesusing a unique horizontal reaction chamber containing a plurality ofnested, horizontally-directed, concentric tubes with offset openings,which can be in the form of narrow slits or small holes. The horizontalreaction chamber of the present invention can prolong the contact timebetween air or gas bubbles and protein loaded water for improving theefficacy of a naturally occurring skimming action for producingprotein-loaded foam. The contact time between bubbles and water isprolonged by the unique arrangement of the plurality of nested,concentric tubes contained within the horizontal reaction chamber.Turbulence is created in the horizontal reaction chamber by acombination of eductors drawing gas to mix with water into the tubingleading to the reaction chamber, high velocity of water moving throughthe concentric tubes, counter-current water movement, and shear force ofwater moving through the small offset openings in each tube.

The outlet compartment of the foam fractionation protein skimmer of thepresent invention can direct the more pure water downward and out whilethe contaminated foam rises to the top. Contaminates in the water attachthemselves to the bubbles and rise to the surface of the water as foamwhich is collected in a foam collection container attached to the top ofa foam riser. The water left behind is substantially more pure and isdirected out of the reaction chamber through a pipe or tube, which canbe made from PVC. The protein removal system of the subject invention isparticularly useful in the aquarium field because it fits into verysmall spaces and requires very little headroom. Additionally, theprotein removal system of the subject invention is sectioned intocomponents which can be easily transported and assembled on-site. Aspecific advantage of the present invention is that the uniquehorizontal reaction chamber can be retrofitted into existing proteinskimmers, which can make it ideal for growing aquaria that need toreplace older protein skimmers that no longer function adequately.

The horizontal reaction chamber of the present invention also allows forincreased contact time between bubbles and water, more efficient bubbleproduction, and substantially more efficient waste removal than existingvertical skimmers. Additionally, the protein removal system of thepresent invention has the advantages of requiring very little headspace,having a very small footprint, and being easy to assemble and maintainthroughout the lifetime of the skimmer. The protein skimmer describedherein is only approximately 2–3′ tall compared to the 8–10′ height ofprior art protein skimmers, yet is able to process large volumes ofwater in a short period of time. Multiple horizontal reaction chambersmay be used simultaneously to increase water purification capacity.

The horizontal reaction chamber can be used in processes where it isdesirable to incorporate or mix small gas bubbles efficiently intoliquids. Such processes may include water purification (e.g., proteinskimmers), food processing, and foam fabrication.

The present invention includes a horizontal reaction chamber to create aturbulent environment for producing a maximum number of bubbles of adesired small size and for maximizing effective contact time between thebubbles and water. This method generates massive numbers of bubbles in asmall, confined space, and eliminates the need for a tall, bulkyreaction chamber requiring a considerable amount of space andmaintenance. Once a gas/water mixture enters the horizontal reactionchamber, the mixture is subjected to high levels of shear force,resulting in fiercely turbulent mixing. The high velocity of thegas/water mixture moving through the concentric tubes and the smalloffset openings, in combination with the counter-current movement of thewater, increases shear force. This results in greater bubble frequencyand smaller bubble size which can optimize removal of organic waste fromwater.

Therefore, in a first aspect this invention provides:

A horizontal reaction chamber for incorporating small gas bubbles into aliquid comprising:

-   -   (A) an inlet for receiving a gas/liquid mixture,    -   (B) a plurality of nested and concentric tubes each having        essentially the same length, including an innermost tube and an        outermost tube,    -   (C) a physical barrier between each pair of adjacent tubes        extending along the length of the tubes, wherein the physical        barriers are generally co-linear with each other, and    -   (D) means for securing the position of the tubes relative to        each other;        wherein each of the concentric tubes contains an opening along        its length such that the openings in adjacent tubes are proximal        to the physical barrier between the adjacent tubes and are on        alternate sides of the barrier such that flow in adjacent tubes        occurs in opposite circumferential directions, and the innermost        tube comprises an outlet.

Therefore, in a second aspect, this invention provides

A protein removal system for removing organic waste from contaminatedwater comprising:

-   -   (A) an injector for providing the contaminated water,    -   (B) an eductor for providing gas into the contaminated water,    -   (C) a manifold for dispersing the contaminated water containing        gas comprising a plurality of ports,    -   (D) a horizontal reaction chamber for creating small bubbles of        the gas in the contaminated water comprising:        -   (1) a plurality of inlets corresponding to the plurality of            ports on the manifold,        -   (2) a set of nested, concentric tubes each having            essentially the same length including an innermost tube, and        -   (3) a physical barrier between each pair of adjacent tubes            extending along the length of the tubes, wherein the            physical barriers are generally co-linear with each other,        -   (4) means for securing the position of adjacent tubes, and        -   (5) an end plate capping one end of the chamber,    -    wherein each of the concentric tubes contains an opening along        its length such that the openings in adjacent tubes are proximal        to the physical barrier between the adjacent tubes and are on        alternate sides of the barrier such that flow in adjacent tubes        occurs in opposite circumferential directions, and the innermost        tube comprises an outlet; and    -   (E) a foam collection chamber which receives the contaminated        water comprising the small gas bubbles from the outlet of the        horizontal reaction chamber, comprising:        -   (1) a foam riser for collecting foam from the top of the            foam collection chamber, and        -   (2) a tube or pipe for allowing purified water to exit the            foam collection chamber.

In a third aspect, this invention provides

A method for removing organic waste from contaminated water from anywater source containing organic-loaded water, such as large volumeaquarium tanks, lagoons, effluent from agricultural applications,wastewater, or other water sources, comprising the steps of:

-   -   (A) mixing the contaminated water with gas,    -   (B) providing a horizontal reaction chamber for creating small        bubbles of the gas in the contaminated water comprising:        -   (1) an inlet for the contaminated water and gas mixture,        -   (2) a set of nested, concentric-tubes each having            essentially the same length including an innermost tube and            an outermost tube,        -   (3) a physical barrier between each pair of adjacent tubes            extending along the length of the tubes, wherein the            physical barriers are generally co-linear with each other,        -   (4) means for securing the position of the adjacent tubes,            and        -   (5) an end plate capping one end of the chamber;    -    wherein each of the concentric tubes contains an opening along        its length such that the openings in adjacent tubes are proximal        to the physical barrier between the adjacent tubes and are on        alternate sides of the barrier such that flow in adjacent tubes        occurs in opposite circumferential directions, and the innermost        tube comprises an outlet directed to a collection chamber; and    -   (C) introducing the mixture of contaminated water and gas into        the inlet of the horizontal reaction chamber so that the        reaction chamber creates a high concentration of small gas        bubbles in the contaminated water resulting in a foam,    -   (D) collecting the foam from the outlet in the collection        chamber and disposing of it, and    -   (E) collecting purified water through a tube or pipe exiting the        collection chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the invention and many of the advantagesof the invention can be better understood by reference to the previousdescription when considered in connection with the accompanyingdrawings, wherein:

FIG. 1 is a schematic illustration of the horizontal protein skimmer ofthe present invention;

FIG. 2 is a schematic illustration of the horizontal reaction chamber ofthe present invention showing flange attachment and single injectorassembly;

FIG. 2A is an end view of the flange at one end of the horizontalreaction chamber;

FIG. 3 is a schematic illustration of the horizontal protein skimmer forsmaller volume water sources;

FIG. 4 is a schematic illustration of the horizontal reaction chambershowing a single injector assembly with inverted eductor arrangement;

FIG. 5 is a schematic illustration of the inverted eductor arrangement;

FIG. 6 is a schematic illustration of the nested, horizontally-directed,concentric tubes, the direction of water movement, the location ofoffset openings, the center line partition, as well as the relationshipof the lateral manifold which distributes the air/water mixture into thehorizontal reaction chamber;

FIG. 7 is a schematic illustration of the nested, horizontally-directed,concentric tubes, the direction of water movement, the location ofoffset openings, the center line partition (i.e., physical barrier), therelationship of the lateral manifold which distributes the air/watermixture into the horizontal reaction chamber, and a single injectorassembly with straight-line eductor arrangement;

FIG. 8 is a schematic illustration of the nested, horizontally-directed,concentric tubes and the direction of water movement as in FIG. 7, withthe location and arrangement of PVC flange bolts shown as well as thefiberglass bolt with partitions on either side holding the nestedconcentric tubes together;

FIG. 9 is a schematic view of the horizontal reaction chamber showingarrangement of PVC flanges, silicone gasket, and perforated cap;

FIG. 10 is a schematic illustration of the assembly of the nestedconcentric tube apparatus which comprises the horizontal reactionchamber;

FIG. 11 is a schematic illustration of the assembly of the nestedconcentric tube apparatus with single injector assembly with invertedeductor arrangement and meters for regulating gas flow which comprisesthe horizontal reaction chamber;

FIGS. 12A and 12B each show a schematic illustration of the offsetopenings in the tubes as a) narrow slits, or b) small equidistant holesof equal size;

FIG. 13 is a schematic illustration of the possible arrangement forusing two horizontal reaction chambers simultaneously with one largediameter (3–8 ft) foam collection chamber;

FIG. 14 is a schematic illustration of the possible arrangement forusing three horizontal reaction chambers simultaneously with one 6′diameter foam collection chamber.

DETAILED DESCRIPTION OF THE INVENTION

The present invention includes a protein skimmer including a horizontalreaction chamber to efficiently remove organic waste from water. Thehorizontal reaction chamber contains a plurality of nested concentrictubes each having at least one opening along its length, preferably aseries of small openings along its length. In addition, there is aphysical barrier positioned between each pair of adjacent nestedconcentric tubes, with the physical barriers extending essentially alongthe entire length of the tubes. There may be one solid partition whichextends through all the concentric tubes to provide the barriers, orindividual barriers may be provided for each adjacent pair of adjacenttubes. The opening or pattern of openings in each concentric tube ispositioned close to the barrier and is offset from the opening orpattern of openings in the next smaller diameter tube, with thedirection of the offset relative to the barriers alternating betweenclockwise and counterclockwise throughout the series of tubes. Theamount of offset is preferably approximately 10° (i.e., alternating from+10° to −10° to +10° to −10°, and so on), however offsets up to 25° orThe openings can comprise narrow slits or a series of small equidistantholes. This orientation of the openings and barriers in the concentrictubes is used to generate fierce turbulence resulting in a large numberof small bubbles, thereby maximizing the effective contact time betweenbubbles and water.

FIG. 1 shows a schematic view of a protein skimmer with a horizontalreaction chamber (1) being supported by a cradle, preferably made of PVC(2). Contaminated water flows through an injector assembly (3), is mixedwith one or more gases (e.g., gas or ozone) through one or more eductors(4), and then is distributed into the horizontal reaction chamber (1)using a lateral manifold (5) with multiple (e.g., four or five) injectorports (6). The injector ports (6) may have valves (30). Inside thehorizontal reaction chamber (1), the contaminated water mixed with gasis forced through narrow openings in a set of nested concentric tubes(7). The gas/water mixture travels around the inner wall of the largestdiameter tube until it hits a physical barrier (16), it is then forcedthrough the narrow openings (161) into the next smaller diameter tubeand travels in a counter-current direction relative to water in the nextlargest tube, and so on. Once inside the smallest diameter tube (8),water is forced out into the foam collection chamber (9) through anopening (191). In the foam collection chamber (9), the foam (201)containing contaminates rises through the foam riser (10) connected witha diameter reduction fitting (31) and is removed through an exit (11).Contaminated foam is cleared using a spray-down and routed to acontainment vessel where it can be removed by pumping. Purified waterexits the foam collection chamber (9) through a pipe or tube (12),controlled by a valve (30).

FIG. 2 shows a schematic view of the protein skimmer with a horizontalreaction chamber shown in FIG. 1, with the horizontal reaction chamber(1) coupled to the foam collection chamber (9) by means of a flange(32). The flanges are attached using flange bolts (34). The flange andflange bolts are preferably made from PVC. An enlarged view of theflange (32) and flange bolts (34) is shown in FIG. 2A. The horizontalreaction chamber (1) has a single injector assembly (3) and the injectorports (6) do not have valves. The injector assembly has an inlet for airand an inlet for ozone, with gas flow controlled by valves (30). Aunidirectional valve (35) is also included on the injector assemblybefore the eductor (4). An additional flange (32′) on the foamcollection chamber (9) allows attachment of multiple horizontal reactionchambers simultaneously.

FIG. 3 shows a schematic view of a protein skimmer with a horizontalreaction chamber (1) for use with smaller volumes of water. It has asingle injector assembly (3) for reduced flow rate.

FIG. 4 shows a schematic view of a protein skimmer with a horizontalreaction chamber (1) with a single injector assembly (3). The injectorassembly has the eductor (4) on the straight portion of the injectorassembly to increase efficiency and stability. Valves (30) are attachedto the eductor to allow fine-tuning of gas flow and meters (33) areattached to valves to allow consistent setting of flow rates. Aunidirectional valve (35) is included to prevent backflow.

FIG. 5 shows a schematic view of an injector assembly. Water travelsinto the injector assembly, through an eductor (4), into the lateralmanifold (5), and enters the horizontal reaction chamber through aseries of injector ports (6). Valves (30) are attached to the eductor toallow fine-tuning of gas flow and meters (33) are attached to allowconsistent setting of flow rates. A unidirectional valve (35) isincluded to prevent backflow.

FIG. 6 shows an expanded view of the interior components of thehorizontal reaction chamber (1) in cross-section. The injector assembly(3) is comprised of an eductor (4) for the gas (e.g., air or ozone) andinjector (6) for the liquid (e.g., water). A water and gas mixture isthereby formed and is injected into the reaction chamber through aninjector (6). The water/gas mixture is injected into the outermost tube(13) at a site (15). Water travels around the outermost tube until itreaches the physical barrier (e.g., a bolt or partition) (16) and thenis forced through a first narrow opening (14) approximately −10° fromthe water injection site (15). The water/gas mixture moves through thenarrow opening (14) into the second innermost tube (17). The water/gasmixture flows in a direction opposite to the direction of water flowingthrough the outermost tube (13). Water travels through this tube (17)until it reaches the barrier (16) and a second narrow opening (18) thatis +10° from the first narrow opening (14) of the previous tube. Watermoves through the second narrow opening (18) and travels through thethird innermost tube (19) in a counter-current direction to the previouswater flow. This process continues until the water/gas mixture reachesthe most central tube (20) of the horizontal reaction chamber.

FIG. 7 shows an expanded view of the interior components of horizontalreaction chamber (1) in cross-section shown in FIG. 6, wherein theinjector assembly (3) has the eductor (4) on the straight portion of theinjector assembly to increase efficiency and stability. Valves (30) areattached to the eductor to allow fine-tuning of gas flow and meters (33)are attached to valves to allow consistent setting of flow rates.

FIG. 8 shows a cross-sectional view of the horizontal reaction chamber.Water enters the horizontal reaction chamber through an injector port(6). The flange (32) on the end of the horizontal reaction chamber isattached by means of flange bolts (34). The nested, concentric tubes aresecured by means of one or more fiberglass bolts (36) which can have PVCresin or baffles on either side to create a barrier to block water flow,forcing water through the small openings (18). Water travels in acounter-current direction and enters into the next smaller diameter tubethrough small openings (18).

FIG. 9 shows a schematic drawing of a horizontal reaction chamber (1)with flanges (32 and 32′) at either end. A gasket (38) and either an endplate or blind flange (39) is at one end of the horizontal reactionchamber. The gasket is preferably made of silicone or other suitablematerial. The end plate is preferably made of acrylic or other suitablematerial. A perforated cap (37) allows a tube carrying water to exit thehorizontal reaction chamber.

FIG. 10 shows an assembly of tubes to result in the nestedhorizontally-directed concentric tube configuration (7) of thehorizontal reaction chamber (1) of the current invention. Increasinglysmaller diameter tubes (21–24) are inserted inside a larger diametertube (25). Each tube has a narrow opening (26) that is offset by a smallangle from the opening in the previous tube in an alternating sequence(i.e., the opening (26) in tube (22) is offset relative to the opening(26) in tube (21) by a small clockwise rotation, whereas the opening(26) in tube (23) is offset from the opening (26) in tube (22) by asmall counterclockwise rotation).

FIG. 11 shows an assembly of tubes to result in the nestedhorizontally-directed concentric tube configuration (7) of thehorizontal reaction chamber (1) as shown in FIG. 10, wherein theinjector assembly (3) has the eductor (4) on the straight portion toincrease efficiency and stability. Valves (30) are attached to theeductor (4) to allow fine-tuning of gas flow and meters (33) areattached to valves to allow consistent setting of flow rates.

FIG. 12 shows examples of the narrow openings (26) that can be used withthe horizontal reaction chamber (1). FIG. 12A shows the opening as anarrow slit (27) in each tube (28). FIG. 12B shows the opening as aseries of small equidistant holes of equal size (29) in each tube (28).

FIG. 13 shows an arrangement of multiple horizontal reaction chambers(1) and a single foam collection chamber (9) coupled with flanges (32)for use of two horizontal reaction chambers (1) simultaneously.

FIG. 14 shows an arrangement of multiple horizontal reaction chambers(1) and a single foam collection chamber (9) coupled with PVC flanges(32) for use of three horizontal reaction chambers with a foamcollection chamber of 6″ diameter. Foam rises in the foam riser (10) andexits through the foam exit (11). An acrylic end plate or blind flange(39) is shown at the end of each horizontal reaction chamber.

The water to be purified is supplied to the skimmer by a pump. Theprimary applications of the current invention have been conducted usingsalt or brackish water (15 ppt–38 ppt), but the invention will likelyfunction in freshwater. The gas/water mixture enters the largest of theconcentric horizontal tubes and is forced through the narrow slit orseries of small holes into the next smaller diameter tube, which is thenforced through the opening in that tube into the next smaller diametertube. Water travels through adjacent tubes in a circumferentialcounter-current movement. The high velocity of the gas/water mixturemoving through the concentric tubes and the small, alternating, offsetopenings, in combination with the counter-current movement, increasesshear force, resulting in greater bubble frequency and smaller bubblesize, which is optimal for removing organic waste from water.

The most central concentric tube carries the water out of the mixingchamber into the foam collection chamber. The foam rises to the top ofthe foam collection chamber and carries contaminates with it. Thismethod generates massive numbers of bubbles in a small, confined space,which eliminates the need for a tall, bulky reaction chamber thatconsumes much valuable space. Bubbles are generated by the shear forceof the high velocity gas/water mixture traveling around the tubes andthrough the narrow slit or series of small holes in each tube into theadjacent tube of increasingly smaller diameter. The combination of highvelocity, high shear force, and forceful turbulence created in thehorizontal reaction chamber of the present invention results in highlyeffective protein skimming from large volume water sources such asaquaria, tanks, lagoons, or other water sources.

The plurality of concentric tubes included in the horizontal reactionchamber is of varying diameters. For water purification (e.g., foraquaria, wastewater), a preferable construction of a horizontal reactionchamber will have a minimum outer diameter of 6″ and a maximum outerdiameter of 12″, with 12″ being the more preferred outer diameter. Theouter diameter is dependent on the desired flow rate, with the smaller6″ outer diameter being more useful for flow rates up to 70 gallons/minand 12″ outer diameter being more useful for flow rates up to 200gallons/min. Flow capacity of a single reaction chamber of the presentinvention can range from 70–300 gallons/min. For example, a preferredconstruction of a horizontal reaction chamber for a protein skimmer foraquaria comprises five concentric tubes of 36″ and of diameters 12″,10″, 8″, 6″ and 4″. A flow rate of 45–90 gallons/min can be achievedusing this construction. Multiple units can be combined to increaseskimming action for larger volume tanks, which may approach 2000gallons/min.

Eductors are used to draw in gas (e.g., air, ozone, oxygen) and thegas/water mixture is distributed into the horizontal reaction chamberusing a manifold with multilateral injectors. Injector manifolds candistribute water at various points along the horizontal reaction chamberto maximize tank coverage. A meter can be attached to valves leading toeductors so that flow rate can be adjusted to maximize efficiency and toadjust to varying protein loads within the water source.

This reaction chamber combines high velocity, high shear force, andcircumferential counter-current water movement within the skimmer toproduce a gas/water contact time unobtainable from any other proteinskimmer. The skimmer can be completely disassembled and, when necessary,any part can be readily and easily replaced. A flange connecting thehorizontal reaction chamber with the foam collection chamber facilitateseasy transport, assembly, disassembly, and maintenance. The skimmer canhave a transparent cover at the end of the horizontal reaction chamberto allow viewing of the mixing action and adjustment of the flow rate tomaximize efficiency. The skimmer fits well into aquarium spaces withlittle headspace as well as in very small areas. The foam productionfrom this protein skimmer is very stable and once the skimmer is set up,very little, if any, additional adjustment is required.

The operation of the protein skimmer with a horizontal reaction chamberis as follows:

Protein-loaded water from an aquarium tank, sump, lagoon, or otherorganic-loaded water source, is pumped into the skimmer. Before enteringthe skimmer, the water is mixed with gas, preferably air or a mixture ofgases, preferably air and ozone, by eductor valves which introduce theair or air/ozone into the water with high velocity. The gas/watermixture is injected into the horizontal reaction chamber through atleast one injector, preferably four to five separate injectors. Onceinjected, the gas/water mixture travels through a series ofhorizontally-directed, nested concentric tubes. The gas/water mixturefirst enters the largest of the nested horizontal tubes and then isforced into the next innermost tube through an opening, which can be anarrow slit or a series of small holes. The holes may be spacedapproximately equidistant from each other and may be of similar or equalsize and shape. For example, narrow slit openings preferably in therange from ¼″ to ¾″ in width can be used, with ⅜″ being the morepreferred width. The slit will generally run along the length of thetube. Alternatively, a series of small holes that runs generally alongthe length of the tube can be used, with the diameters of the holesranging from ⅜″ to ¾″ with ½″ being the preferred diameter of the holes.Preferably, a distance of ¼″ should remain between holes for support ofthe tube. The preferred method of providing the opening is to use theseries of small holes because this results in a considerably more stablestructure.

A physical barrier runs down the centerline of the horizontal reactionchamber, such that it transects each of the concentric tubes except theinnermost one. The physical barrier can be constructed of a variety ofmaterials, including fiberglass (e.g., a fiberglass bolt can be used toform the barrier) and PVC cement or resin material. The physical barriercan also serve to hold the orientation of the concentric tubes relativeto each other. Water from the largest of the nested horizontal tubes isthen forced by the physical barrier into the next innermost tube throughthe narrow slits or series of small holes, and so on, until water entersthe most central horizontal tube.

The openings in the concentric tubes occur at an angle offset from theopenings in the previous tube by a small angle (e.g., 10°), with thedirection of the offset alternating between clockwise andcounterclockwise between adjacent tubes (e.g., between +10° and −10°).Water travels through adjacent tubes in a circumferentialcounter-current movement. This movement increases shear force and breaksair bubbles into considerably smaller air bubbles to increase efficiencyof organic waste removal. The smallest and most central concentric tubecarries the water out of the reaction chamber into the foam collectionchamber. Once in the foam collection chamber, the foam rises to the top,carrying protein and organic contaminates with it. Water exits thebottom of the foam collection chamber substantially more free of proteinand organic contaminates than when it entered.

This horizontal protein skimmer can be readily transported in sectionsand assembled on site. Flanges and flange bolts, preferably made of PVC,are used to couple the horizontal reaction chamber to the foamcollection chamber.

It will be understood that the above-described arrangements of theapparatus are merely illustrative of applications of the principles ofthis invention and many other embodiments and modifications may be madewithout departing from the spirit and scope of the invention as definedin the claims.

1. A horizontal reaction chamber for incorporating small gas bubblesinto a liquid comprising: (A) an inlet for receiving a gas/liquidmixture, (B) a plurality of nested and concentric tubes each havingessentially the same length, including an innermost tube and anoutermost tube, (C) a physical barrier between each pair of adjacenttubes extending along the entire length of the tubes, wherein thephysical barriers are generally co-linear with each other, and (D) meansfor securing the position of the tubes wherein each of the concentrictubes contains an opening along its length such that the openings inadjacent tubes are proximal to the physical barrier between the adjacenttubes and are on alternate sides of the barrier such that flow inadjacent tubes occurs in opposite circumferential directions, and theinnermost tube comprises an outlet.
 2. A horizontal reaction chamber asin claim 1, wherein the physical barrier comprises a bolt.
 3. Ahorizontal reaction chamber as in claim 1, wherein the physical barriercomprises resin or other similar chemical composition.
 4. A horizontalreaction chamber as in claim 1, wherein the openings in the tubes arelocated at most 30° away from the physical barriers.
 5. A horizontalreaction chamber as in claim 1, wherein the openings in the tubes arelocated approximately 10° away from the physical barriers.
 6. Ahorizontal reaction chamber as in claim 1, wherein the openings comprisea series of small orifices.
 7. A horizontal reaction chamber as in claim6, wherein the small orifices are spaced substantially equidistant fromeach other.
 8. A horizontal reaction chamber as in claim 1, wherein theopenings comprise slits.
 9. A horizontal reaction chamber as in claim 1,further comprising an end plate on one end of the chamber.
 10. Ahorizontal reaction chamber as in claim 1 which can be retrofitted intoan existing protein removal system.
 11. A horizontal reaction chamberfor incorporating small gas bubbles into a liquid comprising: (A) aninlet for receiving a gas/liquid mixture, (B) a plurality of nested andconcentric tubes each having essentially the same length, including aninnermost tube and an outermost tube, (C) a physical barrier betweeneach pair of adjacent tubes extending along the length of the tubes,wherein the physical barriers are generally co-linear with each other;and wherein the position of the tubes is secured and each of theconcentric tubes contains an opening along its length such that theopenings in adjacent tubes are proximal to the physical barrier betweenthe adjacent tubes and are on alternate sides of the barrier such thatflow in adjacent tubes occurs in opposite circumferential directions,and the innermost tube comprises an outlet.
 12. A horizontal reactionchamber as in claim 11, wherein the physical barrier comprises a bolt.13. A horizontal reaction chamber as in claim 11, wherein the physicalbarrier comprises resin or other similar chemical composition.
 14. Ahorizontal reaction chamber as in claim 11, wherein the openings in thetubes are located at most 30 degrees away from the physical barrier. 15.A horizontal reaction chamber as in claim 11, wherein the openings inthe tubes are located at most 10 degrees away from the physical barrier.16. A horizontal reaction chamber as in claim 11, wherein the openingscomprise a series of small orifices along the length of each of thetubes.
 17. A horizontal reaction chamber as in claim 16, wherein thesmall orifices are spaced substantially equidistant from each other. 18.A horizontal reaction chamber as in claim 11, wherein the openingscomprise slits.
 19. A horizontal reaction chamber as in claim 11,further comprising an end plate on one end of the chamber.
 20. Ahorizontal reaction chamber as in claim 11 which can be retrofitted intoan existing protein removal system.